Visual Studio SignTool.exe Not Found

Basically, for VS 2015, this would be:

• Open Programs and Features
• Select "Microsoft Visual Studio 2015" and click "Change"
• Press "Modify" to progress to Features options
• Select "Windows and Web Development", then tick "ClickOnce Publishing Tools" for installation
• Then "Next" and then "Update"

The signtool.exe appeared after also installing the sdk:

If you do not care about sign your program when you publish, just right click your project then choose Properties --> Signing --> un-check Sign the ClickOnce manifest .